我使用安装了 postgresql
sudo apt-get install postgresql-9.1 postgresql-9.1-contrib postgresql-9.1-postgis
然后由于某些原因，我需要从系统中卸载 postgresql。卸载方法如下：
sudo /etc/init.d/postgresql stop
sudo apt-get --purge remove postgresql\*
sudo rm -r /etc/postgresql/
sudo rm -r /etc/postgresql-common/
sudo rm -r /var/lib/postgresql/
userdel -r postgres
sudo userdel -r postgres
sudo groupdel postgres
现在我想再次安装相同的版本，但没有找到存储库。我该如何添加存储库并安装？
猫/etc/apt/sources.list给出：
# deb cdrom:[Ubuntu 12.04.2 LTS _Precise Pangolin_ - Release i386 (20130213)]/ precise main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://in.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src http://in.archive.ubuntu.com/ubuntu/ precise main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://in.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb-src http://in.archive.ubuntu.com/ubuntu/ precise-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://in.archive.ubuntu.com/ubuntu/ precise universe
deb-src http://in.archive.ubuntu.com/ubuntu/ precise universe
deb http://in.archive.ubuntu.com/ubuntu/ precise-updates universe
deb-src http://in.archive.ubuntu.com/ubuntu/ precise-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://in.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src http://in.archive.ubuntu.com/ubuntu/ precise multiverse
deb http://in.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb-src http://in.archive.ubuntu.com/ubuntu/ precise-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://in.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://in.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
# deb http://security.ubuntu.com/ubuntu precise-security main restricted
# deb-src http://security.ubuntu.com/ubuntu precise-security main restricted
# deb http://security.ubuntu.com/ubuntu precise-security universe
# deb-src http://security.ubuntu.com/ubuntu precise-security universe
# deb http://security.ubuntu.com/ubuntu precise-security multiverse
# deb-src http://security.ubuntu.com/ubuntu precise-security multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner
## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
# deb http://extras.ubuntu.com/ubuntu precise main
# deb-src http://extras.ubuntu.com/ubuntu precise main
deb http://cz.archive.ubuntu.com/ubuntu precise main
# deb http://qgis.org/debian precise main
# deb-src http://qgis.org/debian precise main
deb http://in.archive.ubuntu.com/ubuntu/ precise-proposed restricted main multiverse universe
和apt-cache 策略 postgresql给出：
N: Unable to locate package postgresql
sudo apt-get 更新：
Get:1 http://archive.canonical.com precise Release.gpg [2,839 B]
Get:2 http://extras.ubuntu.com precise Release.gpg [2,829 B]
Get:3 http://in.archive.ubuntu.com precise Release.gpg [2,839 B]
Get:4 http://archive.canonical.com precise Release [2,835 B]
Get:5 http://in.archive.ubuntu.com precise-updates Release.gpg [2,847 B]
Get:6 http://in.archive.ubuntu.com precise-backports Release.gpg [2,849 B]
Get:7 http://extras.ubuntu.com precise Release [2,825 B]
Get:8 http://ppa.launchpad.net precise Release.gpg [2,856 B]
Get:9 http://ppa.launchpad.net precise Release.gpg [2,865 B]
Get:10 http://ppa.launchpad.net precise Release.gpg [2,848 B]
Get:11 http://in.archive.ubuntu.com precise-proposed Release.gpg [2,848 B]
Ign http://archive.canonical.com precise Release
E: GPG error: http://archive.canonical.com precise Release: The following signatures were invalid: NODATA 1 NODATA 2
答案1
您可以使用 PostgreSQL Apt 存储库。PostgreSQL apt 存储库支持 amd64 和 i386 架构上的 Ubuntu LTS 版本（12.04、14.04 和 16.04）。要使用 apt 存储库
创建文件
/etc/apt/sources.list.d/pgdg.list，并为存储库添加一行：deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main导入存储库签名密钥，并更新包列表：
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add - sudo apt-get update